A sample of molten aluminium is cooled until all of it freezes. No aluminium is lost and no chemical change occurs.
Which statement describes both what happens to the number of aluminium atoms and their arrangement?
The number of atoms increases because close packing reduces the empty space between neighbouring atoms.
The number of atoms is unchanged, and they form a fixed pattern in which they stop moving.
The number of atoms is unchanged, and they are closely packed in a fixed, regular pattern.
The number of atoms is unchanged, and they remain randomly arranged and able to slide past one another.
93 exam-style questions on OCR GCSE Chemistry 1.1 The particle model, covering 1.1.1 The particle model and changes of state and 1.1.2 Limitations of the particle model. Each one has a worked solution and a mark scheme showing where the marks go.